Electric heater.



H. P. BALL.

ELECTRIC HEATER.

APPLICATION FILED FEB. 16, 1910.

1,021,230. Patented Mar. 26, 1912.

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i "ll WITNESSES I T72 5.

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UNITED STATES PATENT OFFICE."

HENRY PRICE BALL, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOB T0 GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

- i ELECTRIC HEATER.

Specification of Letters Patent. Application filed February 16, 1910.SeriaI No. 544,238.

r To all whom it may concern:

, Be. it known that I, HENRY P. BALI; a, citizen of the United States,residing at Pittsfield, in the county of Berkshire, State ofMassachusetts, have invented certain new and useful Improvements inElectric Heaters, of which the following is a specification.

' This invent-ion'relates to electric heatersand the like and has forits object the provision of a device of this characterin which theheating element -or resistance conductor is held in intimate thermalrelation with the body to be heated in asimple and One of the objects ofprovide an electric heater in which the resistance conductor is held incontact with- -the' metallic body to be heated by integral portionsofLthe body itself, so as to approach as closely as possible the actualembedding of'the conductor in the iron. r

Incarrying out my invention I form depress'ions or grooves in themetallic body to be heated and place the conductor in the grooves. -'Thesides of the grooves extend above theconductor and can be bent down overthe conductorto practically inclose it,

condition between the conductor and the In the accompanying drawing, inwhich I have shown lily-invention embodied. in con crete formforpurposes of illustration, Figure 1 is a plan view of the heatingelement Fig. 2 is a sectional view ofthe same mounts edso as to form astove; andFigs 3, 4=and 5 {are detail views showing'the means forsecuring the conductor in place.

'Referrin Y to the "drawings, 10 represents the metallic bod --to beheated. I have shown it in the. orm of afla't disk which is adapted toform a stove. "The under side of the plate' is grooved, as shown, in theforrnof a spiral groove 11, althou h 'it is obvious .that any othersuitable orm of grooving may be employed-.' This plate may have thegrooves formed therein'in various. ways; for instance, the grooves maybe I dropforge d into the disk or the plate may be in the form 015a'malleable casting. The

sides 12' of. the grooves extend abovev the surface of the plate and aretapered, as

' shown. The resistanceconductor- 13 is then prlaced 'in the groove andinsulated there- .om'. This insulation may be produced by windingasbestos or other insulating ma- I V n I u my invention is to odyis'ejfected.

terial around the wire, or by folding a piece of mica around the wire asshownin Fig.

5,-and placing it in the groove. When the conductor is laid in thegroove and insulated from the metal, the ed es of the groove 12 are bentdown over tfie conductor. This may be done in any desired manner, as,for instance, by passing it through suitable rolls. The edges are.pressed, tightly upon the conductor, so as to holdthe latter underpressure and force'it int'o intimate thermal relation with the plate.Heat is .thus conducted away "from the wire to the working surface in avery eflicient manner,'since a large portion of the conductor is incontact with the metal.- The plate is then mounted 'in a frame, asshowmandthe leads brought down to the te'rminalpins15.

I have shown and described my lnvention for purposes of illustration asbeing con- .structed in a. specific manner, but it is obvious that myinvention is not limited either to the particular form ofheater or tothe construction and arrangement of parts herein shown and described,since various modifications will suggest themselves to those skilledinthe art without departing from the spirit of my invention, thescope ofwhich is set forth in the annexed claims. What I claim as new and desireto secure by Letters Patent of the United States, is 1."The process ofmaking electric heaters, which consists in forming a groove in ametallic body to beheated, placing a re:- slstance conductor in saidgroove, and

bending the metal forming the side of the groove over the conductor tohold it se curely in place.

- 2; The process of making electric heatersa which consists in forming aspiral groove ina metallic body to "be heated, placing aresistance'conductor in said groove and bend-;

ing the metal forming-the side of the groove over the conductor to holdit in place.

3. The process of making electric heaters, which consists in grooving-ametallic plate throughout one of its surfaces, placing a resistanceconductor in the grooving and bending the metal over the con uctor tohold it in place.

- 4. An' electric heater comprising a grooved metallic body and aresistance conductor" in said groove and insulated therefrom, the

metal forming the groove being bent over the conductor.

5. An electric heater comprising a plate insulated therefrom, the metalforming the moved on one side and a resistance congroove being bent overthe conductor. 10 (motor in said grooves and. insulated there- .Inwitness whereof, I have hereunto set from, the metal forming one side ofthe my hand this 3rd (1a,v of Feb, 1910.--

groove being bent over the conductor. I HE BY PRICE BALL. 6. An electricheater comprising a plate Witnesses: having a spiral move in one sidethereof H. B. DAVERIN, a resistance con uetor in said groove and r J AB.S. SMYBER.

